Press 'sauté' on the instant pot. Add a small amount of cooking oil of choice (I used avocado). Once hot, add in the beef mince. Break up with a wooden spoon and sauté until browned.
Add in the onions, stir and cook for about 2 mins. Add in the garlic, stir and cook for another minute.
Pop in the carrots, celery and oregano, stir and cook for about a minute and then turn off the sauté function.
Add in the tomato sauce, tomato paste, fresh tomatoes and stock (see notes re stock). Give everything a good stir and then add in the broken lasagna noodles. Stir them in, making sure to cover them with the liquid otherwise they will not cook properly.
Put on the lid, seal and set the pot to 'Manual' pressure cook for 6 minutes.
Once the pot beeps do a 'Quick Pressure Release (QPR)', remove the lid and give everything a good stir. Add in the baby spinach and the cream cheese, give everything a stir, leave for a moment for the cream cheese to melt and then stir again.
Serve immediately with some freshly grated parmesan, fresh basil and red chilli flakes. You may need to add some salt (I usually find I don't have to due to the cheese and tomato paste). This can also be enjoyed the next day but it will be less soupy and more like a lasagna.